Combined muffler and spark arrester



Nov. 15, 1955 J. HALLIDAY El AL 2,723,723

COMBINED MUFFLER AND SPARK ARRESTER Filed June 25, 1952 ZZI/ JV INVENTOR. W :7.

United States. Patent Ofiice CGMBINED MUFFLER AND SPARK ARRESTER John Halliday, Georgetown, and George G. Cole, Kelsey, Calif.

Application June 23, 1952, Serial No. 295,066

4 Claims. Cl. 181-70) contributing toward the protection of fire hazard areas 'from fire, since it is known that fires are often started from sparks discharged with the exhaust, the usual type of muffler being designed only for their silencing efiect with practically no spark arresting capabilities.

This mufiier allows for substantially unrestricted flow of the exhaust gases since the areas at all restrictive points are equal, yet producing violent eddies which cause retention of solids within the mufiler.

The objects and advantages of the invention are as follows:

First, to provide a combined mufller and spark arrester which will eifectively retain solids through eddying or cyclonic action while permitting relatively free exhaust of the gases.

Second, to provide a mufller as outlined with eddy .torming pockets for acceptance and retention of sparks and other solids to provide a spark free exhaust.

Third, to provide a mufller as outlined in which the areas at all restrictions are equal for uniform flow of gases through such restrictive areas.

Fourth, to provide a mufiler as outlined which is simple in construction and eflicient in operation.

In describing the invention reference will be had to the accompanying drawings, in which:

Fig. 1 is a top sectional view taken on a line 1-1 of Fig. 2.

Fig. 2 is a side sectional elevation of the invention.

Fig. 3 is an enlarged view of the initial eddy promoting deflector and is taken on a line 33 of Fig. 2.

The invention is shown rectangular in cross-section and which is the preferred form though not so limited, the rectangular section proving the most efficient, and consists of a box-like structure having a connection 11 for connection to the engine exhaust pipe.

A plurality of battles are fixed within this box-like structure and consisting of an initial upper eddy forming baffle 12 which is provided with a plurality of passages 13 to provide for both, through passage of gases as indicated at 14 and deflection of gases as indicated at 15 with the gases passing through the passages being deflected by a second upper eddy forming bafiie 16 which causes deflection of these gases to the previously deflected gases as they return about the lower edge of the baflie, causing an intermixing and violent eddying as indicated at 17 to cause dropping of the solids as indicated at 18 back of the initial lower baffle 19, the gases then passing over the two spaced lower bafiles 19 and 20 with another expansion occurring between these baflies to drop any remaining sparks or solids, a final deflection occurring when the baflle 21 is reached.

The housing is tapered from the base of the baflle 19 2 to the exhaust end 22, and the minimum space between the terminal end of any baflle and the closest surface is identical with that between the upper and lower edges of the exhaust and, in other words, the area between the edge 23 of baffle 12 and the bottom wall 24, between the end 25 of bafile 16 and the closest point on baflie 19, the edges 26 and 27 of baffles 19 and 20 and the top wall 28, between the edge 29 of baflle 21 and the sloping bottom wall 30, and between the upper and lower edges 31 and 32 of the exhaust end are all substantially identical to provide all restrictions to a predetermined value and with decreased expansions to the exhaust end, the areas being substantially equal to 40% of the area at the initial end 33 of the housing. Thus an eflicient mufiler and spark arrester is provided which is very effective in silencing the exhaust and which retains all solids, thereby protecting areas where fire hazards exist from sparks ordinarily discharged with the exhaust gases.

The baflles are shown at their most efficient angle,

sloping in the direction of the exhaust end at an angle of degrees, thus no back pressure is created as is created when the baflies are vertical or sloping toward the intake end 11. However, this angle should not be below 40 or above degrees, as the efficiency drops ofI as the angle is either decreased or increased.

I claim:

1. A mufiler comprising a housing rectangular in crosssection and having a top wall, a bottom wall, and side walls, an intake end having an exhaust pipe connection, and a discharge end having substantially one-half the cross-sectional area of the intake end, a plurality of upper baffles coextensive with the upper half of the cross-sectional area of the mufller at their respective locations, and a plurality of lower baflles coextensive With the lower half of the cross-sectional area at their respective locations, and with all bafiies inclined in the direction of the discharge end, said baflles including a first upper baflle having its upper end in slightly spaced relation to the intake end, and a second upper bafile in spaced relation toward said discharge end from said first upper baffle, a first lower baflle having its connection to said bottom wall substantially in vertical alignment with the top connec tion for the second upper bafile, and a second lower baflle located in spaced relation toward said discharge end from said first lower baflle, all surfaces and free edges of said bafiles being spaced from the closest adjacent surface or edge of wall or bafi le a minimum distance equal to the height of the discharge end for equal cross-sectional areas of passages, said first upper baflle having passages formed therethrough for diversion of gases simultaneously to the second upper and the first lower baflles to create violent opposing eddies for discharge of solids to the intake end side of the first lower battle with the gases then passing upwardly about the first lower baffie and eddying thereover to the intervening space to the second lower baflle for further deposit of solids between the first and second lower baffles.

2. A structure as defined in claim 1, said housing being uniform in cross-section from said intake end throughout approximately one-third of the length of the housing and thence tapering to the discharge end to approximately one-half the height of the intake end, with the housing uniform in width throughout its length, and with said baflles inclined from their points of connection to the top and bottom walls toward said discharge end at an angle of approximately 45 degrees to the horizontal axis of the housing.

3. A combined mufller and spark arrester comprising a housing having a top wall, a bottom wall, side walls, and an intake end wall having an exhaust pipe connection, and having a discharge end, a plurality of upper and lower baifies mounted in said housing, with the upper and Patented Nov. 15, 1955 lower baflles having their rrpcctive upper and lower edges fixed to the respective top and bottom walls, and their side edges fixed to the side walls, and all inclined in the direction of the discharge end at an angle of substantially 45 degrees to the horizontal axis or" the housing, and including a first upper baffle fixed to the top wall in slightly spaced relation to said intake end wall, a first lower baifie having its lower end connected to the bottom wall substantially in alignment with the plane of said first upper bafile, and a second upper baffle located in a plane substantially in alignment with the upper free edge of the first lower baffie, and passages provided through said first upper bafile for diversion of part of the gases through the passages for deflection by said second upper baffle toward the surface of said first lower baffle with the remainder of the gases deflected in opposition to said deflected part of the gases, by said first upper battle to the bottom wall and thence upwardly by the first lower bafiie for creating violent eddying for deposit of solids on the intake end side of the first lower bat-fie, and a second lower battle in spaced relation from said first lower baffle toward said discharge end for deposit of additional solids from the eddying gases flowing over the top edge of the first lower baffle.

References Cited in the file of this patent UNlTED STATES PATENTS 1,144,306 Mock June 22, 1915 1,804,070 Sykes May 5, 1931 1,975,483 Scott Oct. 2, 1934 2,047,378 Martin July 14, 1936 2,312,242 Dunham Feb. 23, 1943 2,557,687 Rainville June 19, 1951 FOREIGN PATENTS 262,427 Italy Jan. 28, 1929 

